def list_remotes():
"""List available tables in Gaia catalogues.
Returns
-------
tables : list of str
Available tables names
"""
available_tables = Gaia.load_tables()
names = []
for table in available_tables:
name = table.get_qualified_name()
index = name.index(".") + 1
name = name[index:]
names.append(name)
return names
#
# > Running this import statement has the effect of creating a [TAP+](http://www.ivoa.net/documents/TAP/) connection; TAP stands for "Table Access Protocol". It is a network protocol for sending queries to the database and getting back the results. We're not sure why it seems to create two connections.
# ## Databases and Tables
#
# What is a database, anyway? Most generally, it can be any collection of data, but when we are talking about ADQL or SQL:
#
# * A database is a collection of one or more named tables.
#
# * Each table is a 2-D array with one or more named columns of data.
#
# We can use `Gaia.load_tables` to get the names of the tables in the Gaia database. With the option `only_names=True`, it loads information about the tables, called the "metadata", not the data itself.
# In[3]:
tables = Gaia.load_tables(only_names=True)
# In[4]:
for table in (tables):
print(table.get_qualified_name())
# So that's a lot of tables. The ones we'll use are:
#
# * `gaiadr2.gaia_source`, which contains Gaia data from [data release 2](https://www.cosmos.esa.int/web/gaia/data-release-2),
#
# * `gaiadr2.panstarrs1_original_valid`, which contains the photometry data we'll use from PanSTARRS, and
#
# * `gaiadr2.panstarrs1_best_neighbour`, which we'll use to cross-match each star observed by Gaia with the same star observed by PanSTARRS.
#
# We can use `load_table` (not `load_tables`) to get the metadata for a single table. The name of this function is misleading, because it only downloads metadata.
def list_tables(self, table=None):
if self.available_tables is None:
self.available_tables = Gaia.load_tables()
return [table.get_qualified_name() for table in self.available_tables]
